string-not-empty -- r7rs Type string-length;string-ref;string-set!;string->number;string->symbol;string->list;string->vector;string-upcase;string-downcase;string-foldcase;string->utf8;get-environment-variable;syntax-error;string?;string-append;string-copy;string-copy!;string-fill!;substring;string=?;string<?;string>?;string<=?;string>=?;string-ci=?;string-ci<?;string-ci>?;string-ci<=?;string-ci>=?;string-map;string-for-each;open-input-string;write-string;error;Note: These definitions consume an input that is a super-type.
string;make-string;number->string;list->string;vector->string;string-upcase;string-downcase;string-foldcase;utf8->string;(lambda (value) (and (string? value) (not (zero? (string-length value)))))